<html>

<head>
    <style>
    #div1 {
        position: absolute;
        width: 300px;
        height: 300px;
        background: #ccc;
    }
    
    #div2 {
        position: absolute;
        left: 0;
        top: 0;
        width: 200px;
        height: 200px;
        background: red;
        filter: alpha(opacity=50);
    }
    </style>
</head>

<body>
    <div id="div1">lll
        <div id="div2">
            </div>
            </div>
</body>

</html>
